Pemodelan Geoid Lokal Kota Semarang Berdasarkan Model Geopotensial Globalgrace

Abstract

Semarang geoid models determined by gravimetric method. The wavelength components used in the gravimetric method is long-wavelength, medium-wavelength, and short-wavelength. The long-wavelength component obtained from global geopotential model EGM2008, GGM03C, and GIF48 with maximum degree 360. The medium-wavelength component derived from terrestrial gravity, and the short-wavelength component obtained from the topography or terrain. Data processing in the GRAVSOFT shows the undulations gravimetric value of 24.902 meters to 25.596 meters from the EGM2008 models; 25.417 meters to 25.036 meters from the GGM03C models; and 23.746 meters to 24.442 meters from the GIF48 models.GRACEglobal geopotential model evaluation is done by comparing the local geoid undulation pattern of Semarang with the regional geoid undulation pattern of Java, also subtracting the gravimetric undulation and the geometric undulation. The local geoid undulation pattern of Semarang have conformity with the regional geoid undulation pattern of Java. The highest accuracy of the geoid undulation of Semarang generated by the GGM03C model with an error value of 1.48 meters, the lowest accuracy generated by the GIF48 model with an error value of 2.691 meters